1. Field of the Invention
The invention relates to a shaft furnace having a construction comprising a bosh and a shaft (also known as a stack) and a mantle ring (also known as a lintel) at the transition from the bosh to the shaft. This construction has a steel jacket and a refractory lining on the inside of the jacket. Cooling elements arranged for through-flow of liquid extend from the jacket into the refractory lining. An example of such a furnace is a blast furnace.
2. Description of the Prior Art
Such a furnace is known from Dutch patent application NL-A-7312549 (and corresponding U.S. Pat. No. 3,953,007). The cooling elements in the refractory lining of the furnace serve to extend the service life of the refractory lining and in this way to raise the service time of the furnace between repairs. Furnaces of the kind described above particularly furnaces of a relatively older design, are usually provided with a small number of cooling plates of small dimensions. In such furnaces a relatively thin jacket suffices. However, the design entails that the heat control in the transition zone from bosh to shaft (stack) is not optimum and leads to crack formation and leakages.